Duration of efficacy increases with the repetition of botulinum toxin A injections in primary palmar hyperhidrosis: A study of 28 patients

To our knowledge, this study is the first to report a significant increase in the duration of efficacy of botulinum toxin A injections with the repetition of injections in patients with primary palmar hyperhidrosis. The reasons for this effect may be linked to the mechanism of action of botulinum toxin, and may improve our understanding of its pharmacologic effects.